Frames and supports in 15th and 16th-century Southern Netherlandish painting

Brussels, Royal Museums of Fine Arts of Belgium 557 19. Quinten Metsys (workshop), Triptych of the Calvary . Closed: St Adrian ; St Anne Trinity ; unidentified coats of arms. Open: wings: The Donor and his Two Sons ; The Donatrix and her Three Daughters , c. 1530 (?) Inv. no. 1236 Provenance: acquired from Mr Dhuyvetter, Ghent, 1852. Bibliography: Pauwels 1984, 187. Panels: the central panel has three boards, counting in the narrow element in the centre. The reverse has not been thinned, and is flush with the back of the frame. On the inside, the limits of the surface to be painted have been incised into the panel, following the inside contour of the frame. The panel was prepared and painted outside the frame, with the brush strokes ending irregularly at the border and only approximately following the cut lines. Frames: central frame rebated, wing frames grooved. The upper joints are slotted joints, cut square on the outside and mitred on the inside. The lower joints are through mortise and tenon joints (tenon on the stile), cut square on the outside and with a mixed cut on the inside, angled to the sill. The top joints have each two reinforcing pegs, the lower joints single pegs. The central frame is wider and thicker than those of the wings; in the curved part of the central frame, a thickness of roughly 1 cm has been added and pegged originally to the back. Many holes can be seen in the stiles of the closed wings (what is the meaning of these holes?). The thick polychromy is not original.